In a charge pump circuit, boosting/lowering of voltage is generally executed by charging a capacitor through switching. In Patent Document 1 (Japanese Patent Laid-open 2000-262043), there has been disclosed an example of a constant voltage circuit provided with an autonomous adjusting system by which an output voltage of the charge pump circuit is fed back to a power supply voltage of an inverter responsible for a booster action in the charge pump circuit via an output voltage detector and a boosted voltage controller.
Further, in Patent Document 2 (Japanese Patent Laid-open 2000-166220), there has been disclosed an example of a power supply circuit in a charge pump circuit having a booster for generating a high voltage upon receiving a booster clock signal, the power supply circuit being provided with a boosting controller for generating the booster clock signal by comparing an output voltage of the booster with a predetermined voltage. With this example, the output voltage is optionally set, and in order to keep the output voltage at a given level, feeding/stopping of the booster clock signal is executed by the boosting controller.